Heating apparatus



Dec. 18, 1945. w R m HEATING APPARATUS Filed Oct. 25, 1343 2Sheets-Sheet 2 N F w d w I HU UI I I I I HHHH rH u m an l l 1 I ll u Y l:13 u u 1 51 m. Q H Mime. m 9 NTW H Won :Q ilm n i w m E 314--.- mv 0 mO0 .Q m UE mm INVENTOR WILLIAM R. PRICE BY QW,M,M4QW ATTORNEYS PatentedDec. 18, 1945 UNITED STATES PATENT OFFICE HEATING APPARATUS William R.Price, Niagara Falls, N. Y. Application October as, 1943, Serial No.507,378

6 Claims.

This invention relates to electric furnaces and particularly to anelectric vapor generator for use in domestic space heating and in otherinstances Where the requirements and conditions are similar.

According to the present invention means are provided which areespecially adapted to the production of relatively great volumes ofwater vapor or saturated steam at little or no pressure. The objects ofthe present invention are achieved with apparatus which makes itpossible to produce such relatively great volumes without the necessitof maintaining large volumes of water in heated or partly heatedcondition. As an example, the generator set forth herein as anembodiment of the principles of my invention comprises six generatingunits capable of producing a relatively large volume of water vapor orsaturated steam and yet the entire six units contain a normal totalvolume of only about one cubic foot of water.

The design and construction and the proposed system of operation are allsuch as to avoid the usual considerations of pressure and strength whichcomplicate devices of this general nature and render them expensive toconstruct and operate and sometimes also dangerous in use. Further,operating temperatures are such that no particularly refractorymaterials need be employed in the construction of the water reservoirsor pans or in the furnace casing itself or the conduits leadingtherefrom.

The manner in which the several units of the device of the presentinvention are arranged physically with respect to each other makesoperation of the device extremely flexible since the several units maybe serially cut out of operation without affecting the emciency of theunits remaining in operation, despite the fact that operation of theseveral units is interdependent, insofar as units in operation areconcerned.

In addition to the means provided for using any desired number of units,the system is so arranged that an initial applied voltage in excess ofthe normal operating voltage is provided to insure quick startingwithout excess operating temperatures. To this end an initial 220. voltpotential may be automatically cut back to 110 volts when satisfactoryoperating temperature is reached, with the result that the operatingwattage is onl one-fourth that obtaining dur ing the starting period.The system of the present example utilizes a 220 volt three wire A. C.

source and automatically cuts back to the neutral wire for voltoperation after the warming-up period.

An example of one specific manner in which the present invention may bepracticed is shown in the accompanying drawings and is described indetail hereinafter. It is to be understood, however, that variousmechanical and electrical modifications may be introduced withoutdeparting from the spirit or scope of the invention, as defined in theappended claims.

In the drawings:

Fig. l is an elevational view looking at what may be considered thefront of the furnace or pressure generator, with parts of the casingbroken away for added clearness;

Fig. 2 is a rear elevational View;

Fig. 3 is a side elevational view with the outer casing in cross sectionto show the interior arrangement;

Fig. 4 is a detailed cross sectional view of one of the water levelcontrol devices; and

Fig. 5 is a wiring diagram showing the manner in which the several unitsare electrically connected.

Throughout the several figures of the drawings like characters ofreference denote like parts and the numeral I0 designates a generallyrectangular casing for housing the several elements of the generatorillustrated by way of example. The casing contains a series ofsuperposed pans designated ll through it and it will be noted thatalternate pans have their opposite side edges in abutment with one orthe other of the side walls of the casing 10, the opposite side edge ofeach pan being spaced from the other side wall, see Figs. 1 and 2.Reference to Fig. 3 shows that each of the pans H through it extendsfrom front to rear of the casing, so that a tortuous fluid passagebeginning at the bottom and extending laterally across each pan, thenceupwardly, is provided.

All of the pans ll through is have central depressed sump portionsnumbered, respectively, [8 through 23, and these sump portions extendrearwardly through the casing in to form float chambers numbered 24through 29, respectively. The float chamber it is shown in detailedcross section in Fig. 4 and comprises a float 38 pivoted at 3| andadapted, when the water level is at a predetermined maximum as indicatedin Fig. 4, to close a valve post 33 formed at the end of a water supplyconduit 34. Each of the float chambers 24 through 29 have supplyconduits designated 34 through 39, respectively, leading from a manifold40 which is connected with a condensing vessel and reserve water tank 4|disposed in the casing i0 conveniently above the pans H through I6. Itis thus seen that whenever the level of liquid in One of the floatchambers falls, its related float valve will open to restore the levelby gravity feed of water from the cendensing vessel and reserve tank 4!,

Disposed in the several pans H through I6 are electrical resistanceheating elements l2 through M, respectively, which project from a commonsupport 48 which may be in the form of a rigid conduit for containingsuitable wiring for the heating elements. the wiring diagram, Fig. 5,the several units are connected in parallel and may be cut off serially,beginning with the bottom element 41, by opening any of the severalmanual switches 58, which may be located along the support it for readyaccess. It will be noted that the opening of any switch 53 cuts out allof the heating elements" therebelow and this insures that when a partonly of the units are active the active units will be the top one, thesecond one from the top, and so on for as many units as are active.

As has previously been indicated, it is desired that higher voltage beused during the warmingup period, to hasten the same, and to this end Ipreferably employ a three wire 220 volt A. C. supply. In Fig. 5, 5i and52 designate the opposed conductors of such a current supply and 53designates the so-called neutral wire. A thermostatic switch 55 is shownschematically in full line in Fig. 5 in position to apply the full 220volt potential to the several heating elements 42 through 41. When theswitch moves to the dot-and-dash line position, which occursautomatically when the water reaches a predetermined temperature, theapplied voltage is reduced to 110 volts and the power consumption andheat production are reduced to one-fourth of the original value.

The heat sensitive means for controlling switch 56 may be of anyconventional form and is shown as comprising merely a cylinder 51projecting into the uppermost pan H. The interior construction of thecylinder 5'! is conventional and forms no part of the present invention.Devices of this class, including the thermostatic switch 56, arecommercially available.

A manual main control switch is shown at Bi! in the wiring diagram, Fig.5, and in the front elevation, Fig. 1. A filler cap Si is shownassociated with the top of the casing l0 and the numerals 62 and 63designate a pair of conduits which may be utilized as vapor output andcondensate return conduits, respectively. If desired, forced vaporcirculation may be provided by means of external circulating meanswithout affecting the principles of operation of the vapor generatoritself.

From the foregoing it will be seen that a multiple-efiect vaporgenerator is provided whose capacity is selectively adjustable and whoseoperation from the starting period to normal running is automaticallyeifected. It will further appear that the apparatus of the presentinvention is highly eflicient and safe in use. Other advantages willappear to those skilled in the art.

I claim:

1.' A low pressure vaporgenerator comprising a casing, a plurality ofrelatively shallow superposed water pans supported therein in verticallyspaced relation, alternate pans being in abutment with one wall of saidcasing and spaced from the opposite wall, the interveningpans beingspaced from said one wall and in abutment With said As indicated inopposite wall, said pans extending substantially across said casingwhereby to define a zig-zag fluid path extending horizontally over eachof the several pans in series, electrical heating means associated witheach of said pans for heating water therein to generate vapor, and avapor discharge conduit leading from the upper portion of said casing.

2. A low pressure vapor generator comprising a casing, a plurality ofrelatively shallow superposed water pans supported therein in verticallyspaced relation, alternate pans being in abutment with one wall of saidcasing and spaced from the opposite wall, the intervening pans beingspaced from said one wall and in abutment with said opposite wall, saidpans extending substantially across said casing whereby to define azig-zag fluid path extending horizontally over each of the several pansin series, electrical heating means associated with each of said pansfor heating water therein to generate vapor, a vapor discharge conduitand a condensate return conduit at the upper portion of said casing, areceptacle between said pans and the upper end of said casing forreceiv- 7 ing condensate, and float controlled conduit means to each ofsaid pans from said receptacle to automatically maintain predeterminedliquid level in each of said pans by gravity flow from said receptacle.

3. A low pressure vapor generator comprising a casing, a plurality ofrelatively shallow superposed water pans supported therein in verticallyspaced relation, alternate pans being in abutment with one wall of saidcasing andspaced from the opposite wall, the interveningipans beingspaced from said one wall and in abutment with said opposite wall, saidpans extending substantially across said casing whereby to define azig-zag fluid path extending horizontally over each of the several pansin series, electrical heating means as sociated with each of said pansfor heating water therein to generate vapor, a vapor discharge conduitleading from the upper portion of said casing, and water supply meancomprising a reseri voir externally of said casing, adjacent each ofsaid pans, a wate supply conduit and float controlled valve means in,each of said reservoirs for controlling the water level therein, theseveral reservoirs being so disposed with respect to their associatedwater pans that the common water of each pan and reservoir automaticallyestablishes and maintains proper water levels in the several pans.

4. A low pressure vapor generator comprising a casing having a series ofspaced superposed open water pans arranged therein in alternatelystaggered relation to provide a zig-zag fluid path extendinghorizontally over the several pans in series, a vapor discharge conduitand a condensate return conduit at th upper part of said casing, areceptacle between said series of pans and the upper end of said casingfor receiving condensate, and float controlled conduit means to each ofsaid pans from said receptacle to automatically maintain redeterminedliquid level in each cfsaid pans by gravity flow from said receptacle,and electrical heating elements immersed in the several waterpans.

5; A low pressure vapo generator comprising a series of spacedsuperposed water pans each having an electrical heating element therein,a power supply circuit having the several heating elements connectedthereacross in parallel,

switch means in said power supply circ'uit. be- 7 tween each of theseveral heating elements, saidtrolling said switch, said switch beingdisposed in said supply circuit and movable automaticaliy under theaction of the thermally responsive means to switch from full connectionof the supply circuit to connection With the neutral conductor thereofto reduce power consumption to one fourth when the water in theuppermost pan reaches a predetermined temperature, and manual switchmeans in said power supply circuit between each of the severalparallel-connected heating elements, said supply circuit connectingfirst with the heating element of the top pan, then with the next below,and so on, whereby opening of any of said manual switches de-energizesall heating elements in circuit below said switch. WILLIAM R. PRICE.

